A Coplanar Waveguide Fed Hexagonal Shape Ultra Wide Band Antenna with WiMAX and WLAN Band Rejection

In this paper, a coplanar waveguide (CPW) fed hexagonal shape planar antenna has been considered for ultra-wide band (UWB). This antenna is then modified to obtain dual band rejection. The Wireless Local Area Network (WLAN) and Wireless Microwave Access (WiMAX) band rejections are realized by symmetrically incorporating a pair of L-shape slots within the ground plane as well as a couple of I-shape stubs inserted on the bottom side of radiating patch. The proposed antenna has stop bands of 5.05-5.92 GHz and 3.19-3.7 GHz while maintaining the wideband performance from 2.88 - 13.71 GHz with reflection coefficient of ≤ -10 dB. The antenna exhibits satisfactory omni-directional radiation characteristics throughout its operating band. The peak gain varies from 2 dB to 6 dB in the entire UWB frequency regions except at the notch bands. Surface current distributions are used to analyze the effects of the L-slot and I-shape stub. The measured group delay has small variation within the operating band except notch bands and hence the proposed antenna may be suitable for UWB applications

Maxwell's Refrigerator: An Exactly Solvable Model

We describe a simple and solvable model of a device that -- like the "neat-fingered being" in Maxwell's famous thought experiment -- transfers energy from a cold system to a hot system by rectifying thermal fluctuations. In order to accomplish this task, our device requires a memory register to which it can write information: the increase in the Shannon entropy of the memory compensates the decrease in the thermodynamic entropy arising from the flow of heat against a thermal gradient. We construct the nonequilibrium phase diagram for this device, and find that it can alternatively act as an eraser of information. We discuss our model in the context of the second law of thermodynamics.Comment: 9 pages (Main Text + Supplemental Material), 3 figures, to appear in Physical Review Letter

Evaluating FOMC forecasts

Federal Reserve policymakers began reporting their economic forecasts to Congress in 1979. These forecasts are important because they indicate what the Federal Open Market Committee (FOMC) members think will be the likely consequence of their policies. We evaluate the accuracy of the FOMC forecasts relative to private sector forecasts, the forecasts of the Research Staff at the Board of Governors, and a naïve alternative forecast. The Fed reports both the range (high and low) of the individual policymaker's forecasts and a truncated central tendency. We find no reason to consider the truncated version. We find that the FOMC output forecasts were better than the naïve model and at least as good as those of the private sector and the Fed staff. The FOMC inflation forecasts were more accurate than the private sector forecasts and the naïve model. For the period ending in 1996, however, they were not as accurate as Fed staff inflation forecasts.Federal Open Market Committee ; Forecasting

Anti-chiral edge states in an exciton polariton strip

We present a scheme to obtain anti-chiral edge states in an exciton-polariton honeycomb lattice with strip geometry, where the modes corresponding to both edges propagate in the same direction. Under resonant pumping the effect of a polariton condensate with nonzero velocity in one linear polarization is predicted to tilt the dispersion of polaritons in the other, which results in an energy shift between two Dirac cones and the otherwise flat edge states become tilted. Our simulations show that due to the spatial separation from the bulk modes the edge modes are robust against disorder.Comment: 6 pages, 5 figure

Forecasting inflation and growth: do private forecasts match those of policymakers?

FOMC projections are important because they provide information for evaluating current monetary policy intentions and because they indicate what FOMC members think will be the likely consequence of their policies. Results here show that the Blue Chip consensus forecasts are a good proxy for the FOMC views. For example, they match the policymakers' views as closely as do the Board staff forecasts presented at FOMC meetings. Using alternative forms of the Taylor Rule, we show that the Blue Chip consensus and the Fed Policymakers' forecasts have almost identical implications for the monetary policy process.Monetary policy ; Forecasting ; Federal Open Market Committee

Forecasting inflation and growth: do private forecasts match those of policymakers?

Federal Open Market Committee (FOMC) projections are important because they provide information for evaluating current monetary policy intentions and because they indicate what FOMC members think will be the likely consequence of their policies. Knowing the Fed’s objectives, their forecasts, and recent deviations of the economy from the forecasts should be sufficient to understand how the Fed is making monetary policy. Results here show that the Blue Chip consensus forecasts are a good proxy for the FOMC views. For example, they match the policymakers’ views as closely as do the Board staff forecasts presented at FOMC meetings. Using alternative forms of the Taylor rule, the authors show that the Blue Chip consensus and the Fed policymakers’ forecasts have almost identical implications for the monetary policy process.Monetary policy ; Forecasting ; Federal Open Market Committee

Economic news and monetary policy

Economic forecasting ; Monetary policy

Propagating Disturbances along fan-like coronal loops in an active region

Propagating disturbances are often observed in active region fan-like coronal loops. They were thought to be due to slow mode MHD waves based on some of the observed properties. But the recent studies involving spectroscopy indicate that they could be due to high speed quasi-periodic upflows which are difficult to distinguish from upward propagating slow waves. In this context, we have studied a fan loop structure in the active region AR 11465 using simultaneous spectroscopic and imaging observations from Extreme-ultraviolet Imaging Spectrometer (EIS) on board Hinode and Atmospheric Imaging Assembly (AIA) on board SDO. Analysis of the data shows significant oscillations at different locations. We explore the variations in different line parameters to determine whether the waves or flows could cause these oscillations to improve the current understanding on the nature of these disturbances.Comment: 12 pages, 6 figures. Accepted for publication in RA